Milwaukee refractometer question

[aus1230]

Happy 4th everyone! Got a quick question about the milwaukee refractometer.
When mixing my water I'm testing it with my milwaukee refractometer and I always zero it out initially with the provided solution and get 0. When I test my batch of saltwater I get my first reading of 1.025. Just out of curiousty I decide to test it again without zeroing it out and from that point on I get a reading of 1.024.
So I decided to try it again..... I restarted it with zeroing it out again to 0 and retest my water and the initial test is 1.025 and then without zeroing it out again I tested the saltwater and once again received a 1.024. Based off of reading the manual the milwaukee refractometer needs to be zeroed out every time just thought I would come here and look for further confirmation that my initial reading of 1.025 is probably the most accurate. Is that correct?

 

[Lavey29]

I don't zero mine out but maybe twice a year. Never been an issue. Tiny fluctuations in salinity won't matter line 24 or 25.

 

[aus1230]

I don't zero mine out but maybe twice a year. Never been an issue. Tiny fluctuations in salinity won't matter line 24 or 25.

Fair enough and I 100% agree with you.
Just thought I'd bring it to the forum and see if it's something someone else has noticed about theirs. I have a tendency to stress about the little things and wonder..."is that normal" lol!

 

[Lavey29]

Fair enough and I 100% agree with you.
Just thought I'd bring it to the forum and see if it's something someone else has noticed about theirs. I have a tendency to stress about the little things and wonder..."is that normal" lol!

My millwalki is always slightly off compared to my ICP test also for salinity.

 

[aus1230]

My millwalki is always slightly off compared to my ICP test also for salinity.

How often do you get yours sent off for ICP testing?

 

[Lavey29]

How often do you get yours sent off for ICP testing?

2 or 3 times a year

 

[TangerineSpeedo]

Well, They are not the accurate things, I think .0025 error. I think what you are experiencing is differences in temperature over a few minutes. I have one but don't use it much because my place is not climate controlled.
I think for you it will be fine, just be consistent on how you use it. I have five different ways to measure salinity and each one will tell me something different. I use the TM hydrometer for my salt mix and the Hanna handheld to check the tanks.

 

[Lavey29]

Well, They are not the accurate things, I think .0025 error. I think what you are experiencing is differences in temperature over a few minutes. I have one but don't use it much because my place is not climate controlled.
I think for you it will be fine, just be consistent on how you use it. I have five different ways to measure salinity and each one will tell me something different. I use the TM hydrometer for my salt mix and the Hanna handheld to check the tanks.

This is a good point. It never hurts to have a separate method available to check salinity. I.pretty much rely on my alk test after checking salinity because if something was way off then my alk would be too.

 

[VintageReefer]

I rarely zero mine out.

I test salinity all the time. I have same behavior as you. I Will let the sample sit a full minute before reading. That seems to keep the numbers consistent if I hit Read multiple times. I don’t zero it. I will check it a few times a year against a refractometer and a floating hydrometer. It’s never been off for me

 

[Pistondog]

Happy 4th everyone! Got a quick question about the milwaukee refractometer.
When mixing my water I'm testing it with my milwaukee refractometer and I always zero it out initially with the provided solution and get 0. When I test my batch of saltwater I get my first reading of 1.025. Just out of curiousty I decide to test it again without zeroing it out and from that point on I get a reading of 1.024.
So I decided to try it again..... I restarted it with zeroing it out again to 0 and retest my water and the initial test is 1.025 and then without zeroing it out again I tested the saltwater and once again received a 1.024. Based off of reading the manual the milwaukee refractometer needs to be zeroed out every time just thought I would come here and look for further confirmation that my initial reading of 1.025 is probably the most accurate. Is that correct?

As someone else mentioned, the instrument and sample is temperature dependent. Wait a minute or so for the water sample to get to room/instrument temperature for best results.
I calibrate using Randys diy salinity solution. Best to cal around your measurement. My milwaukee always reads 0.001 sg unit high.